This invention relates to an improved heat-dissipating or cooling device for the collector of a traveling-wave tube.
For the purpose of heat dissipation, it is conventional to provide, in a traveling-wave tube, a solid heat-dissipating member associated with the magnetic field device. This heat-dissipating member is apertured for fitting engagement with the collector of the traveling-wave tube. In this arrangement, the collector and the heat-dissipating member are preferably held in close contact at all times to achieve the optimum heat-dissipating effect. In addition, and particularly in a traveling-wave tube of the type in which the tube unit is detachably secured to the magnetic field device fitted with a solid heat-dissipating member, the collector must be readily removable from the heat-dissipating member without impairing the efficiency of heat conduction from the collector to the heat-dissipating member and without the danger of causing troubles such as seizing.
Various proposal have been made to meet these requirements. For example, in one known structure, the heat-dissipating member and the collector are formed to interfit with an appropriate taper. The collector and the heat-dissipating member are threadably joined together by manual control with the aid of a nut formed as a part of the heat-dissipating member. Another known form of a cooling device for a traveling-wave tube collector includes, as disclosed in U.S. Pat. No. 3,586,100, cylindrical collector with no taper and having a slidable fit in a correspondingly apertured heat-dissipating member. In operation, the interfitting collector and heat-dissipating member come into pressure engagement with each other as the temperature rises, thereby to establish an appropriate heat-conducting relation therebetween.
These prior devices, however, suffer from certain drawbacks that are inherent in their design. In the former device, in which a tapered collector is inserted into the heat-dissipating member and firmly secured thereto by turning a nut provided thereon, the collector must be removed to turn the nut reversely with a considerable effort. The second form of cooling device described is subject to physical limitation and high cost, particularly in those cases in which the device is of the natural air-cooling system requiring the formation of large cooling fins on the solid heat-dissipating member.